Recently a new type of automatic assembly tool has been made known which uses a passive spring-loaded mechanism to provide translational and rotational motion. "High Speed Robot Assembly of Precision Part Using Compliance Instead of Sensory Feedback" by Samuel H. Drake, Paul C. Watson, and Sergio N. Simunovic; U.S. patent application Ser. No. 732,286, filed 10/13/76, "Remote Center Compliance System", Paul C. Watson. The rotational motion occurs about a compliance center at, near or beyond the tip of an operator member suspended or in some way supported by that mechanism. The center of compliance is defined as the point where a lateral force causes only a lateral deflection and a torque or moment causes only a rotational deflection. The translational motion portion of the mechanism consists of a number of parallel members, each having two spaced, discrete, hinge or pivot points about which the mechanism translates. The action envisioned in a single plane is that of a four bar linkage parallelogram. The rotational motion portion consists of a number of similar members which extend in the same general direction as the other members but which converge toward the rotational center at the tip of the operator member. Thus the center of rotation is set by the geometry of the converging members.